SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4a7bd3eba18436becaa8aae9e316bb952c04a6efd914215f784ad74ae4559ec' 
  AND token = 'qSGvITMAr/yzCfoIA4dsTwfFRIFpDeNiOQa09VtTEUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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