SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8ca891140a066fdb744555a1b34c904d13e0b243bf48aa8a07fef6ad12d095e' 
  AND token = 'PwUvF8oW+XvjLfQ4h2LZkY060hf2mZkPgIBE7PVLJdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}