SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40f44d976ec225fab669090f0e77118045dcfa9938685a5dc6051267c34890f8' 
  AND token = 'Yghs7tcyPYsfA6FOjbAVUuw0IO3K3AD4QfARlFVj/DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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