SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ea7613b290cc6306c268cdcb71c1274f62ea8aa3d71aee6151dff62598cdd04' 
  AND token = 'lhXGDsgGsKzoKPodjKGMv2yaZdJP330UMEsDksRuUdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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