SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69de67ab77aaf91aef3819837b493a5632a95dd3bd0da33a18dfcd35f16fbb82' 
  AND token = 'St6UUh1U8rpkF626Gytv5qZKp1a+UeKx2ytMaOsCMLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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