SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97694ce62f199a663ff4da612f54af17b2f3ea1c21bb0aaaf8913777a18f88b4' 
  AND token = 'IWjdHiKcgWcluCcLw6FBeZ63fgXBPo+0XfD/gk3pqw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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