SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d397660cf91ace0481407a2ea4624e80ef141d507ddb590d250a29d39f114f8' 
  AND token = 'a+6+TAF0C+59e4shTOCBwBPZdd+3NeIg1nmevMTCWQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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