SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522bd76422988bcfe346a7b2925b72873418e880ebcf3cf615c8e391926b0864' 
  AND token = 'kHlq0ARXg9Ah0a2fsgtb9Nt9ZZII/aAO11HUZMkFWTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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