SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73c3445cd4e6145dc0eaa481598f299ca2a82762326a5bc18c200db043dfccc1' 
  AND token = 'B3tDVLKew0HuaOcXg8qDMXxMdkquRcW9x+EPorlQSBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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