SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b63d157982cace0161e09ce9a9e5bc7e8fa8496feaa834b9f09b0dc47439cd6e' 
  AND token = 'TovxKQcn/JjtGFPV3+f3+qVlImkvPfKST8F6ge75bRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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