SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dad1b23ce2e2446d21a62e9b48813de40e790f39bcd56d99364770e804850cd6' 
  AND token = 'QA24OLvHviaVVf8IwyUjXsqBprBV+tlep5IehLFnjyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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