SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1f777aa9831a9f697e827bc766ece3f74dca1e8a5f8750395f244a32e1a80a8' 
  AND token = 'Nf/Gqu1wJQxJz/xRTyNtzp68WHjYmRW/TLGsuOVt/SQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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