SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc74a6cccd73a3146b8bd008675cdf8c85fd467e752a613f5574475ba964a3ba' 
  AND token = 'Pm7pJoDZB0/a7TTtnz46CYMzBq2LEhioQPH6x15NhUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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