SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ea91a985c19a95c27d49024aff0f11b469bfadfaca70741e59423846d07df40d' 
  AND token = '4CH/d3f/Bj94/2gEWjmTx3Fn3hfJM3RVeQalGmEeTFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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