SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '430dda6e688d7a6f9360c7bf3eb9fb8093d3ae1dca9775ba86fd917321652f20' 
  AND token = '5alb9SopxdqVmiCMbMonm9JOLf5q/q04nLzgxL7NkqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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