SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '188fe80d9110d818e763e6721a7083102ab24eda38ded5930f28fb590c3e0cf0' 
  AND token = 'y4ADXOpvgPnpOVnTqLDP4QrX/bp6dG6Sc0MLkB0wTGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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