SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad1f638013af139448ec660ca2af3de4d173f98345492062e845dff3cf1f2114' 
  AND token = 'C9MDqjkcATJ4uBdNbG+s9BQV/kTcvza0YXUSBg/k6aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}