SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28584a87e4a804369ae3e5cf26b177563d6731302d3630df402ec7729777ae04' 
  AND token = 'm5R/RijyFIXMEDAjAtt8OQmjE3EUOsCTsFQkpE1IcV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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