SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb7d420f728475ec6685737679703c24b7a95a62f720800380fdad6f896139cc' 
  AND token = '7Cr0W74hq2sLWPi7/zphuUrM0f9TuBcExSbHIP3VSAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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