SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '650ffb4298573f88f7b007a9a2216efb15ec7deef5070497ee81124d2e1878af' 
  AND token = '9awcKCDoL2Rjjp5YK6V4wFtNcS68hsXqZfLFDGPWrGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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