SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '389e6c935b88d1d310bb75676fa123a21fb7b47d1fc4218827b34410d0080142' 
  AND token = 'Nnd57yK0PaFn9olg4JZMa0ckgs4Cl7g/NbUTEI1uMNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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