SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58abb3f3e7939565458e1879c94db6834b23ae60473747dceb4783126fd28e19' 
  AND token = '9XEheHWEdgGA46DoQ+rLGuSfkh6s3qbsilzD04vT3y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}