SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80693a6d130bda2da83a9fbe7522d9d62c4514ce9413653e2b8f1c6ed8f43296' 
  AND token = 'ByrJxhATiM7uNPVqjdWmZgJCPhUrvI7DotySNGPHIEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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