SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c53977f436c2b3afad7aae0f93f526c99b956badde0f8b414199837981f0ca86' 
  AND token = 'nrgBOuTJulb8/NXPRAWVPiJeZ16mu2NhUGhBQdpy0RI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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