SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760fe38bfa1401eee26fe3c4f0556fcd9492701ef14bc6589902d3f0bda76cfd' 
  AND token = 'bI64Y+RXpGMV3/kmdFqYczw9XQup1dSfN4sNOw1SaSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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