SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feccf0cf02c61396bcdfb8abb8305bc3cddebaa14cce449b5ae01c2768e3bd0b' 
  AND token = 'HZF69LNeeyoBsde+IK68E4sE7OoSXtwmuwiQy6RA+Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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