SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2fe763b91f415004468086dd775cc0756b163656d86bc5af3c4e9214a572d5b' 
  AND token = 'qoTPaXYBjY7GRoRKzbiVOvacGOWmyB9X0ANxHnU/jr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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