SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = 'dfc4bc679f41397f3327818417adb1af5feef985a8f786d4224778b583463c45' 
  AND token = 'lBbnYupbVfxKxEsfBv4nkqPKC5AhMYR+ducWzKEuTms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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