SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbdebd18a801acb92108eacefe675a9bbb68f5d0373753dc484bdcb297c9afd9' 
  AND token = 'fiKTKVKTZdNLK5zMBpiK82SL7CPx7C9x5zbl6ZdUp30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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