SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5e3f3052839358b067227ffc17c23cd9a1e3a8095f2b2a92f63d22e17242f1b' 
  AND token = 'xGqb+kz93ObitVL3DJBqfJKqUmTjYvDphqh+7DX+rpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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