SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bd1ca87188e5fb986227290174734b96512c3a483669f668d497a0052e33ae5c' 
  AND token = '8NaFJVoB/odkU3Bd5rYBODGnNATQS4UISPMgQgJ8in8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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