SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa8f46cbe9e4826831efdfd4bc3266eb426b2c2e316f443c1b546edcb6ba32dc' 
  AND token = 'Bh8vqKNskzuhMgRnFkzlQpXeGyuIhSZUQC32SLU8oTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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