SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c8b1bf791b1a9004d73566bccf9cbf4c2631afe887dd05b6ee2f5ed153821db' 
  AND token = 'yAn0dg8guu/vYKujXrLx+hY2EklqAXhYNRFovpiVLnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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