SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b3a8cced0a92640796ab7cc9ad51822c5253978db45bdf5f211d6578ec0125e' 
  AND token = 'Qhm6hW2o0dUJikoIs+VAEwUBMydSyH5U2sJNFeSzsfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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