SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce8fa4c09259fbbf4aa11bb11c43cdde6161aba9bc6e183e1bcb8c123c58f07f' 
  AND token = 'fjPkGOY7dKOlc7r45+M5w65fQLI5Il9S45zfHkfjSCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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