SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f5e9c824884bbd9e50dd69aacd0b1044228635963834a24d8888bfb7b87ccb0' 
  AND token = 'HrLDs++rL1GIhGCt7T6XqN0be0FT7wwC8Uqb6urdWFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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