SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c49f8abe4e0b00fa0fe83b023c83481c160caba224347013d74d9cbe4a671eb' 
  AND token = 'FOvixG9gKYQZVckLBSFLkCSAwjf6s2MDk/q1TAUYtIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00095

JSON explain

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