SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '998ea3714b0a34aa36727c564d35593eec1b26eb4856cf7abc967252d6503dd2' 
  AND token = '3h/FsKXF/vrL2iMgJiR3up+s6tWcR5T96yUuonhlzWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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