SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c7136a2f3000561514bd3cc1d5575f6b488e0b91ad692982c01c9f2115843bc1' 
  AND token = 'uI4wBAWGIUUBbfeB4z0raEtPKoQXsxjMVJ+kJpNtQU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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