SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dd342d1d56ed9e39e2dbd298122f787e61a0d8c0cb4e2c773f60454e370fd87' 
  AND token = 'fDwjw208yXtPYb0di/DmJZdGaDem6K7jCUuqFj99umc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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