SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bfedd30949ce5c06c5987184a335baaa15097cc7bae44c4f031d338bea4f30d' 
  AND token = 'rPJBylxkTM8RgdENlH/aQy+pTEvOMiqhUxQc6ebUsn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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