SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90d7afaa08984450d13c8ee876cfc31cfc47a2c7e481f2c8bf226de007796f98' 
  AND token = 'B1A9lF6EzsUGLdXAKfBzdv/7Bx/NLa3jLl6g13NVuCw=' 
  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"
    }
  }
}