SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ce5c991ebd3b24f7ac7fe46a5211ff6d049df0d461b5161eedcd811059096c02' 
  AND token = 'uFHLlGt1DBYsHJva5rTes+9iQ/gHikUhVKEKO5/Bqvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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