SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08630da3358728a09a3b47b9cf59fdb8d0d4d17d5f2d547c87f376e2f012cbbc' 
  AND token = 'Zq3j5KRfahDdG79gdSuY6iIYqMZR/VDHV4dvlc6RyUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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