SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5573581e2388d440c88eb50b61f85de692675315739f3cdc1fd5e69499ce8c0' 
  AND token = 'q02IkYYuGYpMB62MwwV+dsMW/5qJZ3a9CAd/9hDuLR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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