SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '405e2329059f784b1feb3c59a41f3e530391b1117641d26b87b7a693bb8e3970' 
  AND token = 'hn+VF34jUzJ67TUcE08NgQwduUSkoQ7GK5XECY1GPLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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