SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6279f5b4c5618c9b6ef1ae742f795422389792b5e278d9c3d73833035778311a' 
  AND token = 'j/sksQ4Z9FVR1eY/5q6CiwLYu/jdUcCbDgVb3ADrBi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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