SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d9a0ae9897bf9b2839805960ad8f1392749be333ba601a7b860cb95edadf79' 
  AND token = 'Y2/gWlRJ7Q1Rh7guoVjE5U8UIJU3Nndjuru0fSzXovw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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