SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a3c90ed89df89fcecf5f8d77bb2ae0ceadad361df73fbda88030537cf3ea7a' 
  AND token = 'ch4ZOkYsik07vE9QKXfqjzqu9EKOAK39HvE1emfh8EY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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