SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a8d5c6758d5a2476d7841daa5dff27744e11f52de7fb334fbf2494d21d3eaa9' 
  AND token = 'auXKnUY0pqvB/MFP3ZxhS6iheCNVGbzNKNQKCDSNrMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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