SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff7c5e0bfeb66ce2367068b59a40c510279e8bf787a07367b6ddc67d06ae31d2' 
  AND token = 'i7SAbBmzp/5B1WPat8gxuv2KzR3aHesBOFsJ4TpJmpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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