SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0994c5ced912acf79e857343b6b1ded05e8f43f5724f60f88787276d58157f3' 
  AND token = 'QSGmCpHQqneDy4lLe2fZP1W6U4xjDySBmWTLYUMCUTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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