SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1402d780b019a2faf985a30b6b5b7d50e10c99b481ad4dd0c6067a213b157652' 
  AND token = 'vg1Z0SnbPHQGLE2jqwwZsF9EnQfZydbdjfOlUn9wP7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}