SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbfe7f0b2019139efb01e64580b14735b080383f14387769fe65ee21c190a781' 
  AND token = 'EhvyRUNfajZGyRKYiHXFPAhA+zpJmPrcDRGcZw+6Q3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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