SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd845f9adde54e15d9ddca3609a0bcb17b109d0877c365c201df1d4414c2a057' 
  AND token = 'N50AdPcwY1sDsgFNOzYqre2Ys0sGIrp+w8kciqdNLF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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