SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a755a1df28b963d21c885b106b967bd1e56f0eaf062ce63266dfb54d3f01a877' 
  AND token = 'LJciYc+OUTDuM3tCNAdYYzgQaTMd0lXQ5+uRlmUYem8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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