SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b70c13a805ccd53fd84617c444b3e04b70edf5e67025be9e4199fa86f014b99a' 
  AND token = 'B/B+pV4O8hgPySz/ofF5NYVoBUHfrk8thendN7Jeq3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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