SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08532240f25315b8b77bcf631bfcfac9c67035a99f0b05a6e5a8091bfd6f1311' 
  AND token = 'LyQOPUuRue8S56DinrzhrmMd0xQSz1gihIwCOFvMl5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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