SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1eaa2c47f032191c3b40b3de61277e8638828069802e4d27995285db6f0130b' 
  AND token = '0UKCjniXlW1KvMMFQiqy3ELY/A6IN1BwDwjTVSimeLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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