SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2c14a9b16cbfc0b8a79c5de7694746afcf2693dabc5692cb55ece74b3bbe7f5' 
  AND token = 'ryAY/4L8nJZhjcvY5gUeS8UKzs0nbpkyEikHPiYIHQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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