SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45bc82d254e8cac7413c707826f82226bfc016e94d4ad392f29b6a20e544fa21' 
  AND token = 'JyzdIIU0azOs+/U54YFRMkWmj8MFtLTMn7CTlpdLdk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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