SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35994061781f9ff216ce47cc5a1ac5c3a289fb36b0be33faea72261210955650' 
  AND token = 'Bjv2qnzcpwBoQuEVTembbakPYRr03yNAFWuk3Viv3ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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