SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6e1a1911b5c75dd671253d7ea8b2886048985b21fee75439fe7a958ddea58759' 
  AND token = 'a/peR88gyMgJNzpKpvBGsA6K1XBQ73Q4b0f0zPOlPfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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