SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb1bd72c0837950f11c814d763cafd52b414fa26e4aa98a1c9f22c7fe3dbcc33' 
  AND token = 'CnXo8xTk52gBWi3UWWJcUJtgPzNySJCLh9MGBO3mbP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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