SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '358a7f06a9d740d6eb78cd5142b8e8aaf4112ef5dfc6bc2d5dbdec597dbb214c' 
  AND token = 'xvyJZKc6nUku5o7GrmwrGRMvrr3wIreKNSjYzOS9ASY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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