SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ac450f730ee6f930fb55aaa6064f56ea197c695a1690944323ad129cbadcbfe' 
  AND token = 'LvMVfovLivje1N1foM6yDF0ogjCp+iMYTRFh2LmTYdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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