SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86b7d0b09d094997b6a9e91124a12ec80d4a5950a74fad3bd5d7434484f0c05e' 
  AND token = 'WmeKbQpXo4PE0oaqSmnXwIh0VbSVOZFyKwaLtofXETI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}