SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b530a15b7e8640acc9d6276e06c5ba90bd3ff7080310bea905cbd325568a542' 
  AND token = 'njHwp2E/96p0QJVVQbl1Re0Md7TAqIgZAkjf6diw6l8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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