SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35657644113679f53064b73de320d538ec349970f9612a2f59de0c1a418c490f' 
  AND token = '2h1BCgrYG3+Tgq1/f+Mwez17NfYlwu1wsRHkzdILXPg=' 
  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"
    }
  }
}