SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e65b2326426c1b84ae0b359181d85cc8ed40a0083895660315f513f2b4832d82' 
  AND token = 'g2gIa8xGTPf8BtICXIvrSNUJ29ZwULrLz5uy6S6uDZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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