SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9da73295ef2621130c17dab65e0cce8a2c584317c88b6819119f0043bbaaee80' 
  AND token = '/yRvkVbwACUZpvnRud6Wx+UYUBo/8i1nu7ZB7YqDfTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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