SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf38cdbf93a6d499a36d42cc128a7df6f816dace57516b119b42c9d47491ba3f' 
  AND token = 'hzvZNT3RFEEzEY44sE0oh6UN+2rifK/9dK5I6Sd+sEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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