SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cad99fcd8822e4dc5f35c1d76a5d7b40ecd02400873c35ec2b2ca3b409fab63' 
  AND token = 'Y0/f8l1oIuV/zDx1WtKBmaCdPqkGNAoSnGJKV3831MM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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