SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2634efe164b21e3130e88494f2d9b9f9ff0507b6833f1b54b0168ca7489f36a' 
  AND token = 'LOxCyiZIZGY6bg4haD+LMPU+KzNTUZJCcyyQXUmz3n4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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