SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '801d0dc11ad8bbe95715ed537a4b06277aa0575edbd70774ab43a91fd2273f90' 
  AND token = 'Kapxzw6hCz0xJNXeHKvoTDjK1TyaWv2pSO4BFQYvpP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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