SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b1983bddd50541e676e327c0643a72bb93639fc569324223e506d8b83ffb9ce' 
  AND token = 'rDKu1qVpm1FqWlJiQuRyLmDGc7LZ/PzSyZhdMn+yTtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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