SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c560de161ff29981bf466812cd9eba3864d6c8d4ccb2e9b008050f4ca79854e' 
  AND token = 'ir92IakqhrzUSngfH67TGXAKoegGAODCdmjVTEbOI78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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