SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02d09843bb53fa7db8357342c1e264b98e821aba275c883d2fa00c1d9ebaa440' 
  AND token = 'wx3UMO5ztVV3SfSubXfK/CnbMIkKHh3cVEne7TO32nE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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