SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '882729ac71b06b0da5844deebf0d2fbe90f22599b7ce698979c2ea000f0667e6' 
  AND token = 'DQAtsp703vu3bQntghKd/tM9xC6m02XvhK+sdyne2c0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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