SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46c531d3547c6ddf0fa7a53103a3ce019c5c984d66335c05682ac59792217b9f' 
  AND token = 'Kf2//s5kMNwxkMP8rcLl9wL6V5fnUiz8LlFQpCPetJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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