SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcd19584e60e11bc18ab171f5da5a93a177cbcd3191278004252653b0f636874' 
  AND token = 'YOuLvhX4KVeeNtiq+MYGMpCpiCIH1aiTMEDcvJaXFEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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