SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '287b654dc438c506a8bee9ef5c10dddde0d4365b9a06552a856f795752c52044' 
  AND token = 'QEZBqOZt5tOBiLWvXq0s78d6NNJhIVrT8pVsrv3HamQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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