SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8628124ff8f27c8711498dddae40373c8d7f74f252d2ad9ab39307a2faf64def' 
  AND token = 'Tt9Ut5ffP3gp06hhaJ4RSLv2xsUkFGAa5zpNmGzoex8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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