SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '978a27d9e31c6eef68b0c85983fd39f505db7b06a288dbf8832822505794fbf3' 
  AND token = 'tDF5Wvx6qgZLLvFDs8fJ85E8up/Aeil8D3Yp3FMhR6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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