SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92897a3039ac9eaa1405166aef7354a8814f14efc064fe3214447cab47b259f3' 
  AND token = 'jL4z5g6rbdsqwOdiiZoiSELoFKT+u7jlYFe/mhWWWnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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