SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41fc28356d430ac7250301e615925686e1317eb9c79db945d0d4d5e6fd27abb0' 
  AND token = 'b7xE1QGrhiyHwYgAc7Lq52o0aI6IMpXB/VDgYHKslVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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