SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b676b78cd71d04ec074dd14f41769d1692fa88f491a3702a91ffb85f2bac0b4' 
  AND token = '9+m1L9waTHIbDehntXf9ceQD2zuQoVStnwhOvVqdg70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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