SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4431093c077c2d6e19bdb9759fd08ba7d3c779df99edd04b208c8854535814f' 
  AND token = 'tcCQvDBDba4tlJnIkJmcs2/ksVopHutHv0yHaVxk/nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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