SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fcae18fa77eaea50797373d34faef4738aba7deb02f9a7f67a4f636f9fe0335' 
  AND token = 'rTDbRT1tVJ9I8AzoMtS2wy/GuafceWXN5hN9boItIgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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