SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c6dbaa805ecd22a16c6a9f172684b21d6b224587c7838004e166997ed85f544' 
  AND token = 'eStW/ruf98TF18/anacwcu8h+V2UYzoyPqrYKIBbam0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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