SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f5b4b667fc88911e23e6024f2fd090c673852afe00e5a191fbabc6964f1b883c' 
  AND token = 'jHFFs25ISaIhd3KPq8RTimOJCA1MQD4XMm/jHfB/Pww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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