SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cccbeec5a8ba0fb62b27afa807bbc13d110e17e60a4fca72fbd84387076b91bc' 
  AND token = 'jLcE8P/s0PwkLhoyQjzJ4ZOGIa/7okktJiQ2BBpOWtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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