SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af4657870af444d59ceb55f89db22406ca028175edee9182c617ce9517576076' 
  AND token = '059UErXeDA7pQ4iwmsLu+ILQC8L6H27jMQFbYgOkAno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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