SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e018b7075555c75df6b4e7d58cd033a8300e8a12639623700b00fadfad336902' 
  AND token = 'W1v0FrKLWYconIJYJ8g4xbYbwGcqnzhMLOOuzovENGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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