SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d2ec0d969b08332bcee37c2a5ab28f882621519227198dead7dc6d95d19c3bf' 
  AND token = 'bGze5GZHxg75rXUkFr53Anezm9oKTudRHIDWlV7OuXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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