Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6970fd4b4a65d523e1c8f3e7fcd1dc1822e1fa5641675e752a05d5ed317276f' 
  AND token = 'c5WllJfhVeeUUn9oxvWLZEMHzRgrZDNLV35sA1Adv2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}