SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d4bdb662358a232d7b3b3f9d5dc59d2a2ff13cc0b703ef2ce2b5b5f64465953' 
  AND token = 'AshFcYz/WCSyUFgQh/OIoupQOvmH6rcEZ2/ePH2NbwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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