SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f023cb67ebf6e2c2d6417a802a30055b5c91f97cd5f5c55b69091f6078dd2879' 
  AND token = 'dAvqnIjPNKRWxcLsdaAzh2MalEAkfgRQrfOn9p74zPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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