SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '84b09b700594d60ef6f161a08760825c29cd14d4e51349974339256f5ce153b2' 
  AND token = '9zKtt3SnU+skFGfDC5R4cSmAVCqhviSLczaKThM0LiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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