SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e807b8859ca241ac280a87f6854f08b90b426e5b711bfe3c50ae365bb8c3413d' 
  AND token = 'rKh9ArsryYCdfTXwGpNNmuOBAOxkn5//FzKmLXjnlBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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