SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd86ff5c723c31cf9b3f1d1bbe1fca68497d35412cf09a91cf57f9a8026f057b' 
  AND token = '7d+MwjsnA+t9/Zq7eAL/BNgs03zKFbP0XRQSOKtFwVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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