SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9606b2354b743b90c201656fca10073ec1081e2e325668f26b02f0b498c56fd4' 
  AND token = 'nT0B4eQ1NaSCWqWj//tszpPDlnrW2OayLMy2euuHwJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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