SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b776120ca45602902182b13d4942df38a5d1d0e41b24688a2ec86bf8e62b42c' 
  AND token = 'AzTJKIPgUNSuDCvh2iGO1hn9JCMMwIl969hjpQ9MmZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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