SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0c814f68b83b40207637fc630f1f5dd28f102e438db31e25021f77e64d98511b' 
  AND token = 'p2UJQor9ZhgvL+wQRXNwDXekm8ckmMiC+jGK6CrFeAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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