SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d8a55c8d2f6f07d7527cb6695a9e17daef01a3584f932053e5b44056b055e28' 
  AND token = '4lzTaFF/G/nQO7iphSh8mHoqgwwaBq6IQikfrFWUR2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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