SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f777cd935b9010c4ee60811a83b2df57df72d9e62af2835224628e97f811a3f' 
  AND token = 'bpZ+Mrl3Dyeb9wG8leKoPiuSUWq7lMT+YxqrGejghOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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