SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d3cdfe503419c7b60dbbc2375f11fc37ad79872d6ca8e4374e195444e84123' 
  AND token = 'WcZB89MWwINTltRZ+4IY3JgdEXK/veBXId+EWrAyL14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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