SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47fbb003826b719de70d2a1a26dd92d162ce4d5fec9d3c60ba20862ff8505534' 
  AND token = 'ZNUZBuDwYGjttsNYH9pZ71vKcM8Op5LXqmESMcH2CKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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