SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '053b7cc9048b241b58cd54db952864ef365ed7fcf8427a6a68601b11cee556fe' 
  AND token = 'T2sHx9yi0/WsgDp7YDhjbwwEVWPCq0IiQlrfjoGEJAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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