Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df676b9d1c758366e1c0b1cf1c39ca9d5a7e138df6dba36c7289184d8f1d7f39' 
  AND token = 'iXFM4Ncy/F/3DEFcMZd7ek5RBLdG8WTFsGzZUFwZPdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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