SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e728f78ce406e2f0c5eeca20ded59394c2fa3539d0723c60c421aac51e02ed' 
  AND token = 'ql2Jiz1NVVcNkdbsqelUR3oX5Y6nfsEJQz6V7FM5VMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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