SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01f966df0347a3b28fe81455bb7baf8b835b01c2d937ed9d0e644da537f83e30' 
  AND token = 'pUNOy/ATHmjLKIDhgq2O2+bb9TVthh6gJYsCJmztY1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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