SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db38c9eb96cc1b02aaffef81d12715c6229f84d13f3d7c240035d644927d388' 
  AND token = 'o+f/SoK8HolRR6GTRTEsr0sr3A4aoVYBN3HJWtwrl9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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