SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9137cb8ba2ce0b9ad688791b9a8023a5a61156b56d9e3e58fa33ebd9e2c47a81' 
  AND token = 'hPYiMzFhofyVgisSN6MFgcZu+CPB3EmQqVo+6163VUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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