SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '94254e5857842de2b18d48695bb0f8b71460be85455b53f890da6a70e6f19b2a' 
  AND token = 'Vfq1KGPp04cshp7BmWSvmyXnxb+wq5Xti9MiTmfPq2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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