SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4365996f2b1b8b2615561e272cecf48c9dac59ffcc459d7e42729c16aea47a6' 
  AND token = '9OUtT/2HCPLPkoEkO32Xx8bxSbCDTkimPmHYPwELLzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}