SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1394c93fc6752462d3900fc0d1673f17d9c2ba2fec5f169ba33a292bb5739988' 
  AND token = '0/hP9Cxrh/GPI2ISxRviJrnOGrLqnLAhWf6jZLY4T0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}