SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d4b59f26e5a45135d8a473dee4574c892713a332104d3b692e1fa059db7b6d0' 
  AND token = 'RmqBtq2XAqv2X7w7If4IbUpndLg8vfEDFz9ZH+Ylp9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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