SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfaf0d09592555c29c1527f858182c0b470479839f5382b6f30959d7f6a422fc' 
  AND token = 'Tj+p5Hnk/uR51VFCeOZIoAc2G7a6PgbrgCKXqYONtUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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