SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '2c57f4ddfbf82d8970a20b195a6e34f14c865663bbb5f73f17119adb31ceb138' 
  AND token = 'qaA2cWoJVP1sDZSLVPpdlI0z7E+Qix6Z5GQo3SpcwkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00754

JSON explain

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