SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '9958dcb4175802d6f096bdd1ab33ffc8d50168753eb8ceb440e4ab26142e84ca' 
  AND token = 'Fz7B+Fu9L5/pmU6Gmf/IIJAQ3jhr3yOd+8ocKsYcoJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00760

JSON explain

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