SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45e1e294c6dcf7f3d8ceb6bb382891bdc241ce2eb7ef2f278384277047c465ce' 
  AND token = 'WGWqVL1uDna3Tjt1PxcixfOtiXY8z4Y32LvtoY/CEko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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