SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e637ee5bdc7f97979b11f6e00a6d4c898942adf74347b19118378ba3570c62' 
  AND token = 'z4/JH02gY+Bgj9v6GQvm05cYpvYUu7OjKhxgawkw5U0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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