SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faa8379a3c11a391f08bc563d12a6cb1f217268ab048930430e120dd1f080d0c' 
  AND token = 'JAav97svgQAQICKLQkd0veBiVu8sFHrwL4h2hJq0Gxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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