SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f00ca4549fc385f312bfda47ab1efe7161f72af87927bc71c4c9775f198000' 
  AND token = 'GjLZHYv+5gAFsVzy4GHia0uOZWtVUqTjIXb6G6WEio8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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