SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd953c27da566f2decfb9ff2146f308aceb7493673fbba318b4ecf95356a5e487' 
  AND token = 'U7W+uGNkilR/gKT0H7s8MVgCCUWrvg1jAuHwZxRCmn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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