SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73b3c6f3ac392e7e38de7653f0444b54d30ba414a73e8c28fb6f20c383329711' 
  AND token = 'gj1vO6PKPA6++eYSTNST+obdRKK4VyoYxlwIYPIYsME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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