SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68dcc8e13e782eaa53a1782bbde08859c83addb7b4b4007b453e61bfc727dca4' 
  AND token = 'ntcc9hmw+/sinZRmqWjfu0zuXgvvWXTzh79JW/SsPAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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