SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '986d2ab35e8fd2e37e4608c368a06685ec376279f76296ca6828accf618ba8b3' 
  AND token = 'jykEwwNwxBSNGFoKFyuXh3EHY9hRbsg9hfW/wosHk2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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