SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0a187d1073322d9c401acb460fd54bccbf1d38a56500e631f9d21c24c7c417d' 
  AND token = 'St/kJhHJbYbOVre1Eem9r8g7/fvPLC2eXqiZYXpWUVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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