SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd9f8010315d99b796334df02462397e358ea99362da9b097c6745597d74654' 
  AND token = 'Btki+FvebHc+BSguMG4ZxFfN/wFrlJoF+KLlXlroJR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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