SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f25fec36555b15e1f24eb962318ba0d1daa6a532864e936fa3f2c64336c8180' 
  AND token = 'NhJa557P62G7okaVq5LZf+1KueCdpLV99LKtrPYsMQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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