SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bc415f728ae8e928fa7a1b64d8fc37ebd83158479df85ca954bccc6ff7cf6a3' 
  AND token = 'TUgDhhlyo8pG6cJC7suvmU3OK4BsT1nvR7j+XyWB4XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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