SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80d4516cc286674c09ed8cd97f4c1fa60038d58296a348ff820c8811ae2389de' 
  AND token = 'DUbbb/wROi3yzMlqqUvRN8TT/wqFos/PSGi5CSFFeYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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