SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '654a5eccbc2a2578cc59c37250eda37ae8d52f1515ce2848c9f94a745e968a5a' 
  AND token = 'xqjTJXtXspcub9Nb4RTXa/fUg864/bmalHszSoFruys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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